Cm. Pauken et al., MOLECULAR-CLONING, EXPRESSION ANALYSIS, AND CHROMOSOMAL LOCALIZATION OF MOUSE HMG1-CONTAINING SEQUENCES, Mammalian genome, 5(2), 1994, pp. 91-99
We isolated clones encoding the mouse high-mobility-group (Hmg) chroma
tin protein, Hmg1, from a 7.5-day mouse embryo cDNA library. The trans
lated amino acid sequence encodes a protein of 24,890 daltons and is i
dentical to previously characterized mouse, rat, and hamster Hmg1. How
ever, comparison of the two mouse Hmg1 cDNA sequences revealed nine se
quence alterations. This observation, together with the finding of a c
omplex pattern of hybridizing bands in genomic Southern analysis, sugg
ests that mouse Hmg1 is encoded by a multigene family. The expression
of Hmg1 was examined by Northern analysis of RNA isolated from the ear
ly mouse embryo and revealed a predominant 1.5-kb transcript in conjun
ction with low levels of a 2.5-kb transcript. Further analysis of mous
e embryos by in situ hybridization showed that Hmg1 transcripts are ex
pressed in high abundance during early mouse embryogenesis. As develop
ment progresses, Hmg1 transcript abundance is modulated in a spatially
restricted and developmentally regulated manner. Chromosomal localiza
tion with recombinano inbred strains revealed that Hmg1-related sequen
ces are widely dispersed in the mouse genome. Here we also report: the
mapping of six Hmg1 loci to mouse Chromosomes (Chrs) 10, 13, 16, and
17.